Method and apparatus for identifying and skipping defective sections

ABSTRACT

In the case where predetermined data is recorded on the disc in which divided clusters each having a predetermined section are formed in the track, when it is determined during recording that a cluster is a defective section, the recording is stopped and the recording begins again with a cluster offset from the defective cluster, whereby even if there is a partial defect in the track on the disc, the data can be recorded with accuracy.

This is a continuation of application Ser. No. 08/579,838 filed on Dec.28, 1995, now abandoned, which is a Divisional application of 08/211,260filed on Mar. 25, 1994, now U.S. Pat. No. 5,553,045, which is aContinuation of PCT/JP93/01072 filed on Jul. 30, 1993, for A DISCRECORDING APPARATUS AND A DISC RECORDING METHOD.

TECHNICAL FIELD

The present invention relates to a disc recording apparatus forrecording a data on a disc such as a magneto-optical disc, an opticaldisc or the like and a recording method thereof.

BACKGROUND ART

Various kinds of disc recording apparatus for recording a data such asan audio data or the like on a magneto-optical disc and an optical dischave been put into practice in the prior art. When data are recorded onsuch disc, the data are successively recorded in tracks previouslyformed on the disc in a spiral or concentric fashion.

By the way, because of a scratch of a disc surface or the like, a discsuch as the magneto-optical disc, the optical disc or the like sometimeshas a defective portion at a predetermined portion of a track in which adata is recorded. In such case, even if the data is recorded at thedefective portion, then an accurate reproduction thereof is difficult.If an audio signal, for example, is recorded, there is then such a fearthat when the defective portion is reproduced, a reproduced sound breaksoff and a noise is reproduced.

If the defective portion of the track is a very short section, then anoriginal recorded data can be restored by an error correction and aninterpolation processing of a reproduced data or the like, while if thedefective portion is continued for a certain long section, then suchrestoration processing is difficult.

DISCLOSURE OF THE INVENTION

The present invention is made in view of such problems, and an objectthereof is to provide a disc recording apparatus and a disc recordingmethod in which a data can be recorded so that the data can becontinuously reproduced even if a predetermined section of the trackformed on a disc is a defective section.

According to a first invention, in a recording apparatus for recording apredetermined data on a disc in which clusters which are divided at apredetermined section are formed on a track, there are provided a memorymeans for once storing a data, a discriminating means for discriminatingwhether or not the above-mentioned cluster is a defective section, and acontrolling means for performing if the above-mentioned discriminatingmeans discriminates that the cluster under recording is defective, thenthe recording is once stopped and such control that a cluster offset bya predetermined cluster is calculated from the above-mentioned defectivecluster and a data is read again from the above-mentioned memory meansto begin the recording again from the above-mentioned calculatedcluster. Therefore, if a cluster having a defective section is detectedin a track formed on a disc, then the cluster having the defect isavoided and the data is accurately recorded so that the recorded datacan be accurately reproduced upon reproduction.

According to a second invention, a program recorded by theabove-mentioned recording apparatus is formed of one or a plurality ofparts. The above-mentioned disc has a managing information area in whicha managing information formed of at least a start address, an endaddress and a link information corresponding to each of theabove-mentioned parts is recorded. If the cluster under recording isdetermined as a defective one, then control is performed in such amanner that an end of a cluster preceding the above-mentioned clusterdetermined as the defective one is defined as an end address and isregistered as the first part in the above-mentioned managing informationarea and the cluster offset by a predetermined cluster is calculatedfrom the above-mentioned cluster determined as the defective one, theend of the above-mentioned calculated cluster is defined as a startaddress and registered as the second part in the above-mentionedmanaging information area, and a link information of the first partindicates the above-mentioned second part. Therefore, by a recordedinformation in the managing information area of the disc, the clusterhaving the defective section is avoided and it can be easily controlledto continuously reproduce the recorded data.

According to a third invention, a defective area of the above-mentioneddisc is formed of one or a plurality of parts. The above-mentioned dischas the managing information area in which the managing informationformed of at least the start address, the end address and the linkinformation corresponding to each of the above-mentioned parts isrecorded. If the cluster under recording is determined as the defectiveone, then control is performed in such a manner that the start and theend of the above-mentioned cluster determined as the defective one arerespectively defined as the start address and the end address andrecorded in the above-mentioned managing information area. Therefore,the data can be reproduced by determination of the start address and theend address so that the defective portion should be avoided.

According to a fourth invention, the discriminating means fordiscriminating whether or not the above-mentioned cluster is thedefective section is arranged so as to perform the discrimination bydetecting turbulence of an error signal detected by an optical block forrecording a data on the disc. Therefore, the defective section can bediscriminated satisfactory.

According to a fifth invention, the discriminating means fordiscriminating whether or not the above-mentioned cluster is thedefective section is arranged so as to perform judgement by detectingthat a position information from a recording track is discontinuous.Therefore, the defective section can be discriminated satisfactory.

According to a sixth invention, in a disc recording method which recordsthe predetermined data on a disc in which a cluster divided at apredetermined section is formed on a track, there are performed such arecording which is formed of a step of discriminating whether or not adata of a predetermined cluster amount is stored in a memory, a step ofindicating a start of the recording in case of the data of thepredetermined cluster amount being judged to be already recorded uponthe above-mentioned discrimination, a step of discriminating a defect ofthe disc, a step of stopping the above-mentioned recording in case ofthe defect on the disc being discriminated upon the above-mentioneddiscrimination, a step of calculating a position offset by apredetermined length from the above-mentioned defective section, and astep of indicating another recording from the above-mentioned calculatedposition. Therefore, the recording in which the defective portion isavoided can be performed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a structural diagram showing a recording and reproducingapparatus to which one embodiment is applied.

FIG. 2 is an explanatory diagram showing a cluster forming stateaccording to one embodiment.

FIG. 3 is a structural diagram showing an address-data storing stateaccording to one embodiment.

FIG. 4 is a schematic diagram used to explain a track forming stateaccording to one embodiment.

FIG. 5 is a schematic diagram used to explain the track forming stateaccording to one embodiment.

FIG. 6 is a flowchart showing a recording processing according to oneembodiment.

BEST MODE CARRYING OUT THE INVENTION

One embodiment of the present invention will hereinafter be explainedwith reference to the accompanying drawings.

In the present embodiment, the present invention is applied to arecording and reproducing apparatus of a magneto-optical disc on whichan audio data is recorded. Construction of the recording and reproducingapparatus is shown in FIG. 1. In FIG. 1, reference numeral (1)represents a magneto-optical disc. The magneto-optical disc (1) isloaded on the recording and reproducing apparatus and rotated by aspindle motor (3) and is housed in a cartridge (2). Then, a recordedsignal recorded by a magnetic-field modulation method, which will bedescribed later, on a track formed in a spiral fashion on the disc (1)is read by an optical pickup (4), and a reproduced signal is suppliedthrough an RF amplifier (5) to a modulation and demodulation processingcircuit (6) to demodulate the data modulated for the recording. As aprocessing of modulation and demodulation for the recording in themodulation and demodulation processing circuit (6), a digital modulationcalled an 8-14 modulation (EFM), for example, is performed. Theprocessing in the modulation and demodulation processing circuit (6) iscontrolled by a system controller (20).

In each track formed on the magneto-optical disc (1), an address data ispreviously recorded by wobbling (meanderring), and this wobblinginformation is detected by an address decoder (9). That is, thereproduced signal output by the RF amplifier (5) is supplied to theaddress decoder (9), and the decoder (9) decodes the address datarecorded by the wobbling to supply the decoded address data through themodulation and demodulation processing circuit (6) to the systemcontroller (20).

The audio data demodulated by the modulation and demodulation processingcircuit (6) is supplied to a memory controller (10) and once stored inan RAM (11) connected to the memory controller (10). The RAM (11) is adata buffer for continuing an output of the audio data in case of thereproduced data being broken temporarily, and the data stored in the RAM(11) is supplied to a compression and expansion processing circuit (12).Then, the data compressed for the recording is expanded into an originaldata amount thereof by the compression and expansion processing circuit(12), and the expanded data is converted by a digital/analog converter(13) into an analog audio signal to supply the analog audio signal to anaudio signal output terminal (14).

Further, the movements of the optical pickup (4) and a recording head(18), which will be described later, in a radius direction of the discare carried out by the drive of a feed motor (8) under the control of aservo controlling circuit (7) based on a command from the systemcontroller (20). The servo controlling circuit (7) is supplied with thereproduced signal output from the RF amplifier (5) and performs servocontrol to make the optical pickup and the recording head follow thereproducing track. The spindle motor (3) is also rotated by the controlof the servo controlling circuit (7).

The recording system is constructed such that after the analog audiosignal obtained at an audio signal input terminal (15) is converted byan analog/digital converter (16) into a digital audio data, the digitalaudio data is subjected to a compression processing by the compressionand expansion processing circuit (12), the compressed audio data issupplied to the memory controller (10) and once stored in the RAM (11)connected to the memory controller (10), the audio data read out fromthe RAM (11) is modulated for the recording by the modulation anddemodulation processing circuit (6), and the modulated audio data issupplied to a head driving circuit (17) to drive the recording head(magnetic head) (18).

The recording head (18) is disposed just above a position where a laseris irradiated on the disc (1) from the optical pickup (4) (opposite sideof the disc). Upon recording, there is performed a processing in which amagnetic field generated by the recording head (18) is recorded while arecording portion is heated by a laser beam irradiated on the disc (1)from the optical pickup (4). The recording processing is one called amagnetic-field modulation recording system.

The system controller (20) is connected with an operation key (21), andthe recording and reproduction are controlled on the basis of anoperation by the operation key (21). Further, the system controller (20)is connected with a display unit (30) formed of a liquid crystaldisplay, which displays a data concerning the recording and reproductionby a letter, a number or the like.

Upon the recording of the data, the system controller (20) alsodiscriminates existence or absence of a defect of a track underrecording. That is, during the recording of the data, the wobblinginformation (the address data) of the track under recording which isread by the optical pickup (4) is detected by the address decoder (9).The address data detected by the address decoder (9) is checked by thesystem controller (20) during recording, which discriminates whether ornot the detected address is kept continued and determines a portionlacking the address data as the defective section in case of existenceof a portion where the detected address is discontinuous. A state of atracking error signal (signal indicating the tracking of the recordingtrack) detected by the servo controlling circuit 7 on the basis of thesignal read by the optical pickup (4) is discriminated by the systemcontroller (20), which also determines a corresponding portion as thedefective section in case of detection of a large turbulence of thetracking signal.

On the magneto-optical disc (1) of the present embodiment, a subdata canbe recorded besides the audio data. The subdata is recorded in a mostinner periphery track in a predetermined format. Before the audio datais recorded on and reproduced from the magneto-optical disc (1) (forexample, when the disc (1) is loaded on the recording and reproducingapparatus), the subdata recorded in the predetermined track isreproduced and then stored in a memory in the system controller (20).Then, a recording address and a reproducing address for the recordingand reproduction, respectively, are controlled on the basis of thesubdata. When the audio data is recorded, there is performed such aprocessing that a data such as a recorded address or the like is addedto the subdata (that is, the subdata of a corresponding area isprocessed for updating). Only the subdata is often updated by an editingor the like.

Content of the subdata and data arrangement thereof will be explainedhere. As the content of the subdata, a setting state of the track numberset in the disc (1), the address data of each track number and a dataconcerning kinds of the recorded data are recorded. As the address datain this case, data of the cluster number and the sector number arerecorded. The cluster will be explained. The track formed on the disc(1) is divided into predetermined sections which are defined asclusters, and as shown in FIG. 2, successive numbers are given to eachcluster starting from the inner periphery side (in FIG. 2, referenceletter n represents a cluster number). When the data is recorded, therecording is performed by defining one cluster as a minimum unit. Thesubdata thus recorded in the most inner periphery track is called a TOC(Table of Contents: index informations).

Each subdata is divided into areas each having 8 bits and recorded asshown in FIG. 3. The track number described here is the number given toeach of recording units into which the audio data recorded on the disc(1) is divided, for example, the number given to every song in case ofmusic being recorded in one disc. The number does not have any directrelation with the track number of the data recording track formed on thedisc (1).

A block of the audio data of the above-mentioned one recording unit isdefined as a program.

The data to be recorded on the disc is not required to be recorded withphysically continuous addresses and may be discretely recorded.

For example, in a disc represented by a conventional compact disc or thelike, as shown in FIG. 4, the data is continuously recorded in such amanner that the first music of the track number is defined as T1 and thesecond music thereof is defined as T2. However, the data may bediscretely recorded, so that as shown in FIG. (5), the data can bediscretely recorded on the disc as shown by T4 (1) to T4 (4) and T5 (1)to T5 (4) which are respectively defined as the fourth music of thetrack number and the fifth music thereof. (FIGS. 4 and 5 areschematically shown, and practically one section is recorded in aconcentric or spiral fashion over several to several hundred circles.)

The reason why the data can be discretely recorded as described above isthat since the data is once stored in the RAM (11) and then recorded onthe disc, even if the recording head is accesses T4 (2) of the fourthmusic from T4 (1) thereof and then the data thereof is recorded on thedisc as shown in FIG. 5 mentioned above, there is enough time for suchprocess.

The TOC (Table of Contents: the index informations) managing theabove-mentioned discretely recorded data is formed of the address dataat every track number and the data concerning the kind of the recordeddata.

As shown in FIG. 3, if N audio data from the track number 1 to the tracknumber N (reference letter N represents an optional integer) arerecorded on the disc (1), then a data indicating which area the addressdata of the track number 1 is stored in is recorded in an area 49, andhereinafter data indicating the recording areas of the address data ofthe corresponding track numbers to the track number N are successivelyrecorded in the areas one by one.

After an area 304, eight areas are used as one set, and the one unit isdefined as a part.

In the part, a start address of the part is recorded in the first threeareas. A classification data is recorded in the next one area. An endaddress of the part is recorded in the next three areas. A connectiondata is recorded in the next one area.

The above-mentioned part corresponds to one block of the discretelyrecorded data (T4 (1) in FIG. 5, for example, or the like), for example.

The above-mentioned start address and end address correspond to anabsolute address of one block of the discretely recorded data on thedisc, for example.

If one track number is divided and recorded in a plurality of parts,then the above-mentioned connection data is a data for connecting therespective parts. If music of corresponding track number is formed ofone or a plurality of parts, then 00 is recorded as the connection dataof the last part, so that 00 is discriminated to thereby determine theend of the music.

As the classification data, classification of the audio data to berecorded (distinction between a stereophonic data and a monophonic data,existence or absence of a copy guard, on or off of emphasis or the like)is recorded.

In the above-mentioned description, construction of the TOC (Table ofContents: the index informations) about a recorded area has beendescribed, while construction of the managing information about arecordable area will hereinafter be explained.

As shown in FIG. 3, there is recorded a P-FRA (Pointer for the FreelyArea) 48 indicating which address on the above-mentioned indexinformation the recordable area begins with. In the P-FRA, the addressin the above-mentioned index information indicating a part correspondingto a head of the recordable area (which corresponds to an F(l) shown bya broken line in FIG. 5, for example) is recorded.

In the above-mentioned indicated part, a start address of the recordablearea is recorded. A classification data is recorded in the next onearea. An end address of the part is recorded in the next three areas. Aconnection data is recorded in the next one area. If the recordableareas discretely lie on the disc (see FIG. 5), the respective recordableareas are connected to each other by the connection data. Uponrecording, the recording is performed while the above-mentioned indexinformations are retrieved.

As shown in FIG. 3, a P-DFA (Pointer for the Defective area) 46indicating a defect on the disc is further recorded in theabove-mentioned index information. In a similar way to theabove-mentioned P-FRA, an address in the index information managing thedefective area on the disc is stored therein, so that the connectiondata of the part indicated by the above-mentioned address is searched,whereby it can be managed where the defective area is located on thedisc.

Further, as shown in FIG. 3, 255 parts as the index information can bemanaged, and a P-Empty (Pointer for the empty slot on the parts table)47 indicating a use state of the above-mentioned part is recorded. Theabove-mentioned P-Empty indicates a head part of unused parts in theabove-mentioned index information, and the unused parts are connected toeach other by the connection data.

It is needless to say that the parts of the above-mentioned recordedareas, the parts of the above-mentioned recordable areas, the parts ofthe defective areas and the unused parts are mixedly recorded on thesame index information.

It is needless to say that the sum of the number of the parts used inthe above-mentioned recorded area, the number of the parts used in theabove-mentioned recordable areas, the number of the parts in thedefective area and the number of the unused parts becomes 255.

When the data is recorded by the recording and reproducing apparatus ofthe present embodiment, on the basis of the result such that the systemcontroller (20) discriminates existence or absence of the defect of thetrack under recording, the recording address is controlled so that therecording is carried out except for the defective section. A processingupon recording in case of the recording of the audio signal willhereinafter be explained with reference to a flowchart in FIG. 6.

If there is a command for starting the recording (at step 101), then itis determined whether or not a recording data of one cluster unit whichis a minimum unit of the recording data is stored in the RAM (11) (atstep 102). If the recording data of one cluster amount is storedtherein, then the optical pickup (4) and the recording head (18) accessa cluster on the disc (1) in which the data can be recorded (at step103) and the recording of the data is started (at step 104). At thistime, it is simultaneously determined from discontinuity of thereproduced address data and the turbulence of the tracking error signalwhether or not a section having a defect is detected (at step 105). Ifthe defect is not detected, then the recording is continued as it is.When the recording of one cluster amount is finished (at step 106), itis determined whether or not the recording is continued (at step 107).If it is determined that the recording is continued, then the process isreturned to step 102 and the recording in each cluster is continued.Alternatively, if it is determined at step 107 that the recording isstopped, then the processing for finishing the recording is performed.As the processing for finishing the recording, there is performed suchprocessing that the number of the head cluster of the recorded clustersand the number of the last cluster thereof are added to the subdata asthe start address and the end address of the address data recorded inthe most inner periphery track (see FIG. 3), respectively.

If the section having the defect is detected at step 105, then therecording at this time is stopped and data of the start address and theend address of the address data to be recorded in the most innerperiphery track (see FIG. 3) are made (at step 108) on the basis of therecording state up to the last cluster recorded. At this time, theconnection data is added following the end address, and the connectiondata indicates the part number which begins with a cluster two-clusterahead. The data of one cluster amount stored in the RAM (11) is recordedin the cluster two-clusters ahead (at step 109). After the recording ofthe data of the one cluster amount is finished, the process is returnedto a data recording processing for the next cluster.

A processing upon the detection of the defect will concretely beexplained. When the clusters are formed as shown in FIG. 2, for example,if the defect is detected in the recording track in n cluster, then theaddress data is added at step 108, whereby the previous n-1 cluster isdefined as the end address and the connection data indicates such partnumber that the recording begins with an n+1 cluster (one-clusterahead). Then, the recording is continued from the n+1 cluster.

The recording processing is thus performed, whereby if there is thedefective section, then such processing is performed where the data isrecorded with the cluster having the defect being avoided and theconnection data added to the address data directs reproduction incontinuous clusters before and after the cluster having the defectivesection. Accordingly, when the disc on which the data is thus recordedis reproduced, if a cluster just preceding the defective section isreproduced, then the address data directs a skip to the next cluster, sothat the processing for continuing the continuous recording from thecluster next to the defective section is performed. Therefore, even ifthe disc (1) has a partial defect, then the data can be correctlyrecorded and reproduced without causing the lack of the recording data.

In this case, in the recording and reproducing apparatus of the presentembodiment, the reproduced data is once stored in the RAM (11) and thensubjected to an expansion processing to reproduce the same, so that ifan access position of the optical pickup (4) is moved by one clusteramount while the reproduced data is stored in the RAM (11), then thesound to be reproduced is prevented from breaking off.

In the present embodiment, the defective section is discriminated bydetecting the turbulence of the tracking error signal detected by theoptical system and detecting the discontinuity of the addressinformation reproduced from the recording track, so that the defectivesection can be discriminated with satisfactory accuracy.

The defective section may be discriminated in such a manner that whenthere is the turbulence of the tracking error signal or thediscontinuity of the address information, the cluster is not immediatelydiscriminated as the defect, but after the recording in the same clusteris repeated a predetermined times, and when the cluster is repeatedlydiscriminated as the defect, the cluster is determined to be a defectivesection. Such arrangement allows the defective section to be morereliably discriminated.

In the above-mentioned embodiment, if there is the defective section,then the defective section is not registered especially in the indexinformation and dealt with as an unmanaged information, while thedefective section may be defined as the above-mentioned P-DFA (Pointerfor the Defective area) 46 indicating the defect on the disc to registerthe above-mentioned defective cluster as the part.

When the defective section is registered as the above-mentioneddefective cluster, the P-Empty which is the unused part is retrieved torecord the start address and the end address of the above-mentioneddefective cluster in the above-mentioned unused part and if thedefective section is the first defective area, then the address data ofthe above-mentioned registered part is recorded in the P-DFA.

In the present embodiment, when there is the defective section, only thecluster having the defective section is skipped and the recording beginswith the next cluster, while the recording may be continued from thecluster other than the cluster next to the defective section.

Further, while in the present embodiment the address data is allrecorded only in the most inner periphery track, the address data may berecorded in another portion.

Further, while in the present embodiment the recording processing of thedisc on which the audio data of music or the like is recorded has beenexplained, it is needless to say that the present invention can beapplied to the case where another data such as a video data, a programdata or the like are recorded on the disc.

I claim:
 1. A disc recording apparatus, comprising:a disc shapedrecording medium having tracks that are divided into a plurality ofsections; means for recording data to said disc; discriminating meansfor discriminating whether the section of the disc under recordation isdefective, the discriminating means utilizes turbulence of an errorsignal for said discrimination of the section for a defect, wherein saidturbulence of said error signal is detected by an optical block forrecording data on the disc, said discriminating means sensing defectivesections by sensing a turbulence of said error signal exceeding apredetermined amount; and controlling means for controlling saidrecording means wherein if said discriminating means discriminates thatthe section under recording is a defective one, then the recording isstopped and a section offset is calculated from said defective sectionto identify a calculated section that follows said defective section,and said recording means is moved to said calculated section whererecordation begins again; wherein said calculated section immediatelyfollows said defective section on said disc.
 2. The disc recordingapparatus of claim 1, wherein said error signal is a tracking controlerror signal.
 3. The disc recording apparatus of claim 1 furthercomprising:a managing information area located on said disc thatcontains at least a start address, an end address and link informationcorresponding to different parts of a recorded program recorded on thedisc, wherein during recordation, if the section of the disc underrecordation is determined to be defective, then said controller stopsrecordation at the section preceding the defective section and saidpreceding section is defined as an end address of one of said parts andis registered as such in said managing information area, and the sectionoffset is calculated from said preceding section to identify thecalculated section which is defined as a start address of another ofsaid parts and is registered as such in said managing information area,and link information of said one part to said other part is recorded insaid managing information area.
 4. The disc recording apparatus of claim3, wherein said error signal is a tracking control error signal.
 5. Arecording method for recording predetermined data on a disc havingtracks which are divided into predetermined sections, the recordingmethod comprising the steps of:commencing recordation of the data intothe sections on the disc; discriminating whether a section subject torecordation is defective by utilizing turbulence of an error signalwherein said turbulence of said error signal is detected by an opticalblock for recording data on the disc, said discriminating step sensingdefective sections by sensing a turbulence of said error signalexceeding a predetermined amount; stopping said recording in case of adefect being discriminated in a section subject to recordation on thedisc; calculating a position offset by a predetermined length from saiddefective section; and restarting the recording from said calculatedposition again; wherein said calculated position is a beginning of asection immediately subsequent to said defective section on said disc.6. The recording method of claim 5, wherein said error signal is atracking control error signal.